[src/trunk]: src/sys/arch/powerpc/oea there is no need to keep pvos for unman...

[chs <chs%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/fbc8cc72849d
branches:  trunk
changeset: 1022448:fbc8cc72849d
user:      chs <chs%NetBSD.org@localhost>
date:      Mon Jul 19 14:49:45 2021 +0000

description:
there is no need to keep pvos for unmanaged mappings on a hidden p/v list,
since "unmanaged" means that we don't want to find such pvos on any p/v list.
instead, just don't put such pvos on any p/v list at all and remove
the two hidden p/v lists for unmanaged mappings.  code mostly from martin,
to implement rin's suggestion of unifying the two hidden lists.

diffstat:

 sys/arch/powerpc/oea/pmap.c |  52 +++++++++++++++++++++-----------------------
 1 files changed, 25 insertions(+), 27 deletions(-)

diffs (147 lines):

diff -r d8fd10f855e6 -r fbc8cc72849d sys/arch/powerpc/oea/pmap.c
--- a/sys/arch/powerpc/oea/pmap.c       Mon Jul 19 10:30:36 2021 +0000
+++ b/sys/arch/powerpc/oea/pmap.c       Mon Jul 19 14:49:45 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.106 2021/06/27 12:26:33 martin Exp $        */
+/*     $NetBSD: pmap.c,v 1.107 2021/07/19 14:49:45 chs Exp $   */
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
  * All rights reserved.
@@ -63,7 +63,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.106 2021/06/27 12:26:33 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.107 2021/07/19 14:49:45 chs Exp $");
 
 #define        PMAP_NOOPNAMES
 
@@ -328,8 +328,6 @@
 
 TAILQ_HEAD(pvo_tqhead, pvo_entry);
 struct pvo_tqhead *pmap_pvo_table;     /* pvo entries by ptegroup index */
-static struct pvo_head pmap_pvo_kunmanaged = LIST_HEAD_INITIALIZER(pmap_pvo_kunmanaged);       /* list of unmanaged pages */
-static struct pvo_head pmap_pvo_unmanaged = LIST_HEAD_INITIALIZER(pmap_pvo_unmanaged); /* list of unmanaged pages */
 
 struct pool pmap_pool;         /* pool for pmap structures */
 struct pool pmap_pvo_pool;     /* pool for pvo entries */
@@ -652,7 +650,7 @@
        if (pg_p != NULL)
                *pg_p = pg;
        if (pg == NULL)
-               return &pmap_pvo_unmanaged;
+               return NULL;
        md = VM_PAGE_TO_MD(pg);
        return &md->mdpg_pvoh;
 }
@@ -1410,22 +1408,19 @@
 
        if (PVO_MANAGED_P(pvo)) {
                pvo_head = pa_to_pvoh(pvo->pvo_pte.pte_lo & PTE_RPGN, NULL);
-       } else {
-               if (pvo->pvo_vaddr < VM_MIN_KERNEL_ADDRESS) {
-                       printf("pmap_pvo_check: pvo %p: non kernel address "
-                           "on kernel unmanaged list\n", pvo);
+               LIST_FOREACH(pvo0, pvo_head, pvo_vlink) {
+                       if (pvo0 == pvo)
+                               break;
+               }
+               if (pvo0 == NULL) {
+                       printf("pmap_pvo_check: pvo %p: not present "
+                              "on its vlist head %p\n", pvo, pvo_head);
                        failed = 1;
                }
-               pvo_head = &pmap_pvo_kunmanaged;
-       }
-       LIST_FOREACH(pvo0, pvo_head, pvo_vlink) {
-               if (pvo0 == pvo)
-                       break;
-       }
-       if (pvo0 == NULL) {
-               printf("pmap_pvo_check: pvo %p: not present "
-                   "on its vlist head %p\n", pvo, pvo_head);
-               failed = 1;
+       } else {
+               KASSERT(pvo->pvo_vaddr >= VM_MIN_KERNEL_ADDRESS);
+               if (__predict_false(pvo->pvo_vaddr < VM_MIN_KERNEL_ADDRESS))
+                       failed = 1;
        }
        if (pvo != pmap_pvo_find_va(pvo->pvo_pmap, pvo->pvo_vaddr, NULL)) {
                printf("pmap_pvo_check: pvo %p: not present "
@@ -1620,7 +1615,7 @@
        }
        if (flags & PMAP_WIRED)
                pvo->pvo_vaddr |= PVO_WIRED;
-       if (pvo_head != &pmap_pvo_kunmanaged) {
+       if (pvo_head != NULL) {
                pvo->pvo_vaddr |= PVO_MANAGED; 
                PMAPCOUNT(mappings);
        } else {
@@ -1628,7 +1623,8 @@
        }
        pmap_pte_create(&pvo->pvo_pte, pm, va, pa | pte_lo);
 
-       LIST_INSERT_HEAD(pvo_head, pvo, pvo_vlink);
+       if (pvo_head != NULL)
+               LIST_INSERT_HEAD(pvo_head, pvo, pvo_vlink);
        if (PVO_WIRED_P(pvo))
                pvo->pvo_pmap->pm_stats.wired_count++;
        pvo->pvo_pmap->pm_stats.resident_count++;
@@ -1728,7 +1724,9 @@
                pvo->pvo_pmap->pm_stats.wired_count--;
 
        /*
-        * Save the REF/CHG bits into their cache if the page is managed.
+        * If the page is managed:
+        * Save the REF/CHG bits into their cache.
+        * Remove the PVO from the P/V list.
         */
        if (PVO_MANAGED_P(pvo)) {
                register_t ptelo = pvo->pvo_pte.pte_lo;
@@ -1760,15 +1758,15 @@
 
                        pmap_attr_save(pg, ptelo & (PTE_REF|PTE_CHG));
                }
+               LIST_REMOVE(pvo, pvo_vlink);
                PMAPCOUNT(unmappings);
        } else {
                PMAPCOUNT(kernel_unmappings);
        }
 
        /*
-        * Remove the PVO from its lists and return it to the pool.
+        * Remove the PVO from its list and return it to the pool.
         */
-       LIST_REMOVE(pvo, pvo_vlink);
        TAILQ_REMOVE(&pmap_pvo_table[ptegidx], pvo, pvo_olink);
        if (pvol) {
                LIST_INSERT_HEAD(pvol, pvo, pvo_vlink);
@@ -1861,9 +1859,10 @@
        PMAP_LOCK();
 
        if (__predict_false(!pmap_initialized)) {
-               pvo_head = &pmap_pvo_kunmanaged;
+               pvo_head = NULL;
                pg = NULL;
                was_exec = PTE_EXEC;
+
        } else {
                pvo_head = pa_to_pvoh(pa, &pg);
        }
@@ -1952,7 +1951,6 @@
                        else if (pmapdebug & PMAPDEBUG_EXEC)
                                printf("[pmap_enter: %#" _PRIxpa ": marked-as-exec]\n",
                                    VM_PAGE_TO_PHYS(pg));
-                               
 #endif
                }
        }
@@ -2010,7 +2008,7 @@
         * We don't care about REF/CHG on PVOs on the unmanaged list.
         */
        error = pmap_pvo_enter(pmap_kernel(), &pmap_pvo_pool,
-           &pmap_pvo_kunmanaged, va, pa, pte_lo, prot|PMAP_WIRED);
+           NULL, va, pa, pte_lo, prot|PMAP_WIRED);
 
        if (error != 0)
                panic("pmap_kenter_pa: failed to enter va %#" _PRIxva " pa %#" _PRIxpa ": %d",